Railway car brake mechanisms



Aug. 22, 3967 1 G. A. PELIKAN RAILWAY CAR BRAKE MECHANISMS 9 Sheets-Sheet 1 Filed March 3],, 1965 TINVENTOR: 42291965 4. psu (A/v BY Aug. 22, 1967 G. A. PELIKAN RAILWAY CAR BRAKE MECHANISMS 9 Sheets-Sheet 2 Filed March 31, 1965 N My mm fi T 4 N mp m W an .14 M

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RAILWAY CAR BRAKE MECHANISMS Filed March 31, 1965 9 Sheets-Sheet 3 INVENTOR @am: 4. /%z//r,4/v BY 967 G. A. PELIKAN 3,337,606 RAILWAY CAR BRAKE MECHANISMS Filed March 31, 1965 9 S11eets-Sheet 4 g INVENTOR.

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RAILWAY CAR BRAKE MECHANISMS Filed March 31, 1965 9 Sheets-Sheet 6 A T RNE Y5.

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RAILWAY CAR BRAKE MECHANISMS Filed Marph 31, 1965 9 Sheets-Sheet 8 Aug. 22, 1967 e. A. PELIKAN 3,

RAILWAY CAR BRAKE MECHANISMS TIEIJD- Filed March 31, 1965 9 Sheets-Sheet 9 INVENTOR. 4 50/9 A. Z/KA/V United States Patent 3,337,006 RAILWAY CAR BRAKE MECHANISMS George A. Pelikan, Closter, N.J., assignor to Buffalo Brake Beam Company, a corporation of New York Filed Mar. 31, 1965, Ser. No. 444,236 15 Claims. (Cl. 188--59) ABSTRACT OF THE DISCLOSURE A railway car truck in which brake discs are mounted rigid with the car wheels for rotation therewith, the brakes being applied to the brake discs by means of toggle-joint mechanisms, constructed from brake head levers, with legs articulated at one end to form elbow joints, the braking power being applied to these joints tending to straighten them out by bringing the legs towards alignment. Stop means are also provided operable independently of the resistance offered by the braking means, to limit angular movements of the legs into and out of braking positions.

The present invention relates to railway car brake mechanisms especially of the freight type and is an improvement upon the inventions shown and described in Busch US. Patents 2,903,096, 2,903,097 and 2,903,098.

One object of the present invention is to provide a new and improved brake mechanism of the general type described.

Another object of the present invention is to provide a new and improved brake mechanism of the general type described, which has a lesser number of parts, and which consequently is of simpler construction.

Other objects, features and advantages of the invention are apparent from the following description and from the accompanying drawings, in which FIG. 1 is a top plan view of a railway car truck having braking mechanisms constituting one embodiment of the present invention;

FIG. 2 is a vertical section of the railway car truck taken approximately along the lines 22 of FIG. 1;

FIG. 3 is a vertical detail section of the railway car truck taken along the lines 3-3 of FIG. 2;

FIG. 4 is a vertical section of the railway car truck taken along the lines 4-4 of FIG. 1, but shown on a larger scale;

FIG. 5 is a fragmentary top plan view of the railway car truck showing one of the braking units shown in FIG. 1, but shows said unit on a larger scale;

FIG. 6 is a top plan view of a railway car truck having braking mechanisms constituting another embodiment of the present invention;

FIG. 7 is a vertical section of the railway car truck taken on lines 7-7 of FIG. 6;

FIG. 8 is a top plan view of part of the railway car truck shown in FIG. 6, but shows said part on a larger scale;

FIG. 9 is a vertical section of the railway car truck taken on lines 9-9 of FIG. 8;

FIG. 10 is a top plan view of one of the brake head levers in the railway car truck of FIG. 6;

FIG. 11 is a side view of part of the brake mechanism in the railway car truck of FIG. 6, including the brake head lever of FIG. 10;

FIG. 12 is a top plan exploded view of the end parts of two elements of a brake mechanism unit in the construction of FIG. 6 including the brake head lever of FIG. 10; and

FIG. 13 is a detail section of part of the brake mechanism in the railway car truck of FIG. 6, taken on lines 13-13 of FIG. 11. i

Referring to FIGS. 1-5 of the drawings, there is shown a railway car truck comprising a pair of side structures or frames 10 having respective guide openings 11 to receive the ends of a conventional truck bolster 12 extending between said frames and projecting at the ends into said openings, where they are supported on coil springs (not shown) and are guided by side columns 13 of said openings for vertical shock-absorbed movement. The bolster 12 is provided at its ends with lugs 14- engaging the inboard sides of the side columns 13 of the side frames 10 and lugs (not shown) engaging the outboard side of the side columns. These lugs 14 guide the bolster 12 for vertical movement.

The bolster 12 is also provided with a center conformation 16 for direct pivotal connection to the underside of the railway car body in a conventional manner. Between the two side frames 10 and supported thereon by suitable bearings are two parallel axles 17 carrying on opposite ends flanged car wheels 18 which ride on rails 19.

To support certain operating parts of the brake mechanism and at the same time to sustain the side frames 10 against the stresses of the braking action, there are provided two horizontal parallel equalizer bars 20 on opposite sides of the bolster 12, each bar pivotally connecting at its end by means of hinge pins with brackets 22 welded or otherwise fixedly secured to said side frames.

The equalizer bars 20 secured to the side frame brackets 22 through the hinge pins 21 as described, assist the bolster 12 in maintaining the truck side frames 10 in alignment or parallel to the respective rails. The equalizer bars 211 and the truck side frames 10 form a parallelogram, and since these are pivotally joined through the brackets 22 and the hinge pins 21, they operate as a parallel motion permitting the side frames to shift relatively endwise and into limited angular positions with respect to the equalizer bars 20 when the wheels 18 are rounding a curve. The equalizer bars 20 also serve to support the weight of the brake mechanisms.

The brakes for the four car Wheels 18 of each car truck are operated by four similar brake head levers or brake support arms 25, each having an L-shaped lever part, one leg 26 of which is pivotally connected to the corresponding bracket 22 by the corresponding hinge pin 21, and the other leg 27 carrying at its end a brake head 28 by means of a pivot pin 30. The brake head 28 carries a face plate 31 with a brake shoe 32 for application to a brake rotor or disc 33, which is aflixed to the corresponding wheel 18 on the inboard side thereof to stop said disc and which presents a brake face on its inboard side.

For securing each equalizerbar 20 to the corresponding pair of side frame brackets 22, the two hinge pins 21, which pivotally connect the two brake head levers 25 to said brackets, also pass through the ends of the equalizer bar. To provide the hinge connection between a side frame bracket 22 and a corresponding brake head lever 25 in a manner to permit anchoring of one end of the equalizer bar 20 to said connection, the bracket has a pair of spaced superposed projections 35 and 36 straddling a projection 37 in the lever 25 to form a knuckle joint therewith, and these projections are retained in interconnected pivotal relationship by the hinge pin 21 passing through holes in said projections. The equalizer bar 20 is in the form of an angle, one horizontal leg 38 of which is seated at each end upon the lower projection 36 of the corresponding side frame bracket 22 and at said end has a hole through which the corresponding hinge pin 21 passes. The other leg 39 of the equalizer bar 20 extends vertically.

In order to afford a large bearing area between the equalizer bar 20 at each end and the corresponding hinge pin 21, there is welded or otherwise rigidly affixed to the leg 38 of the equalizer bar at each end over the hole in said leg, a collar 40 located between said'leg and the projection 37 on the corresponding brake head lever 25 and embracing the hinge pin with a snug rotative fit. This collar 40 serves not only to provide extra bearing surface for the equalizer bar 20 but also serves to afiord clearance for a support member 41 secured to the equalizer bar to support the corresponding brake head lever 25. This support member 41 is shown in the form of an inverted channel bar secured to the leg 38 of the equalizer bar 20 and having a smooth upper bearing surface on which the brake head lever 25 seats. To provide a wear surface on the brake head lever 25 for that purpose, the lever has a wear shoe 42 welded or otherwise formed on the brake head lever and presenting a smooth surface for smooth slide contact with the support member 41. To make the four brake head levers 25 interchangeable, each of these levers 25 has two of these wear shoes 42 on opposite sides thereof at the intersection of its legs 26 and 27.

As a feature of the present invention, the two brake head levers 25 on each side of the bolster 12 are connected together for unisonal operation into and out of braking position. For that purpose, each of the brake head levers 25 has a third leg 45 integral with and extending transversely from the intermediate section of the leg 27 and generally along the bolster 12. The two legs 45 of the two brake head levers 25 on each side of the bolster 12 have respective confronting end sections 46 offset slantingly from the main bodies of said legs in opposite directions, so that these offset end sections are substantially parallel. A pivot pin 47 passing through the confronting offset end sections 46 of these two lever legs 45 pivotally connects the two legs together at an angle to each other of less than 180 on the outer sides thereof opposite to the bolster confronting sides thereof to form therebetween an elbow joint constituting part of a toggle-joint mechanism. The pivoted lever legs 45 are long enough and so related positionally to the corresponding brake discs 33, as to maintain the angle described between said legs, in either braking or released position of the brakes.

Two toggle-joints are provided on opposite sides of the bolster 12 for operating the four brake head levers 25 into braking positions.

The toggle-joint lever legs 45 are supported for horizontal movements by means of support brackets 50 shown in the form of angles, each having one vertical leg 51 secured to the vertical leg 39 of the corresponding equalizer bar 20, as for example, by rivetting, and having one horizontal leg 52 spaced above the horizontal leg 38 of the equalizer bar to seat the corresponding lever leg 45 thereon. The support brackets 50 cooperate with the support members 41 to properly support the brake head levers 25 for horizontal angular movements into and out of braking positions.

For applying braking power to the junctions of the toggle joints, there is provided a live inclined lever 55 extending between the offset confronting end sections 46 of a pair of lever legs 45 on one side of the bolster 12 and held in this position by the pivot pin 47 passing through said lever leg end sections and through the intermediate region of said live lever 55. The upper end of this live lever 55 is pivotally connetced by means of a pivot pin 56 to one end of a pull or power rod 57 operated from a lever (not shown) of the air cylinder (not shown). This air brake cylinder is supported in the usual manner on the railway car body and forms part of the conventional air brake equipment. The lower end of the live lever 55 is pivotally connected by means of a pivot pin 58 to one end of a connecting rod 60 passing underneath and across the bolster 12 from one side to the other side of said bolster. The other end of the connecting rod 60 is pivotally connected by means of a pivot pin 61 to the lower end of an inclined dead lever 62, substantially parallel to the live lever 55 and extending between the offset confronting end sections 46 of the pair of lever legs 45 on said other side of the bolster. This dead lever 62 is held in this inclined position by the pivot pin 47 passing through said lever leg end sections and through the intermediate region of said dead lever. The upper end of the dead lever 62 is pivotally connected by means of a pivot pin 63 to one end of a rod 64, the other end being pivotally connected to an anchor bracket (not shown), which in turn is secured to the underside or body (not shown) of the railway car.

The connecting rod 60 is provided with at least two pivot holes 65 at each end to permit adjustments in the effective length of said rod, to compensate for wear in the brakes, and is retained against accidental dislodgment from its intended position in the linkage system by means of safety supports 66, two being shown in the form of U-shaped yokes, connected to the vertical legs 39 of the equalizer bars respectively on opposite sides of the bolster 12. The connecting rod 60 passes loosely through these supports 66, and is prevented thereby from dropping accidentally onto the road bed.

In the operation of the brake mechanism so far described, when the brakes are to be applied, the rod 57 is pulled to the right (FIG. 1) by the air cylinder (not shown), and this causes the live lever 55 to rotate counterclockwise (FIG. 1) about the axis of the pivot pin 47. This moves the connecting rod 60 to the left (FIG. 1) and thereby rotates the dead lever 62 counterclockwise about the axis of the corresponding pivot pin 47, thereby moving the anchor rod 64 to the right (FIG. 1) until limiting position is reached, in which case, the rod 64 will be anchored against further movement to the right. In this limiting position of the anchor rod 64, any further movement of the pull rod 57 to the right will cause the dead lever 62 to swing counterclockwise about the pivot pin 63, and this causes the pivot pin 47 carried by said dead lever to move towards the left. By this action, the two brake head levers pivotally connected to the dead lever 62 will be moved angularly by toggle action about the axes of their respective pivot pins 21 into position to apply the brake shoes 32 on the brake heads 28 carried by the brake head levers 25 into braking position with respect to the corresponding brake discs 33.

With the brake levers 25 associated with the dead lever 62 immobilized by the braking action described, the continued pull on the rod 57 to the right (FIG. 1), swings the live lever 55 counterclockwise (FIG. 1) about the pivot pin 58, thereby moving the pivot pin 47 carried by said live lever to the right (FIG. 1). This action moves the two brake head levers 25 associated with the live lever 55 angularly about the corresponding pivot pins 21 into position to apply the brake shoes 32 on the brake heads 28 carried by said brake head levers into braking position with respect to the corresponding brake discs 33.

Although the operation of the brakes has been described as being applied in sequences upon the two pairs of brake head levers 25 on opposite sides of the bolster 12, this sequential operation is not necessarily followed,

, but all of the brake head levers may, more or less, operate substantially imultaneously, until the brake head levers 25 are all in braking position. In this position, the brake head levers 25 mutually cooperate, so that any one or associated pairs of brake head levers 25 reaching immobilized braking position, will serve as an anchor by which the other brake head levers 25 will move relative thereto into braking position.

In the operation of the brake mechanisms as described, the application of power at the junctures of the two togglejoints formed by the two pairs of associated brake head lever legs 45, tends to straighten out the brake head lever legs in each pair and thereby transmits outward pressure to these legs at an enormous mechanical advantage. This transmitted pressure moves the brake head levers 25 angularly about the axes of their pivot supports 21. During the application of braking power to the toggle-joints, the outer angular relationship of the two lever legs 45 of each toggle-joint remains less than 180. Upon release of the brake, spring means (not shown) may be applied, either through the pull rod 57, or through the brake head levers 25, as shown in the aforesaid Busch Patent No. 2,903,098, to return the brake head levers into inactive positions.

FIGS. 6-12 show a modification in which parts similar to those in the construction of FIGS. 1-5 are referred to with the same numbers except for the subscript a. Except as otherwise noted, the construction of FIGS. 6-12 is the same as that of FIGS. 1-5.

In the modification of FIGS. 6-12, the brake head levers 25a are similar to the brake head levers 25 in the construction of FIGS. l-S except for features limiting the relative angular movements of the two coopenating legs 45a of each toggle-joint during braking action, as will be described. For powering the toggle-joints, there is provided an inclined live lever 55a, which has its lower end extending between the offset confronting end sections 46a of a pair of lever legs 450 on one side of the bolster 12a and which is held in this inclined position by a pivot pin 47a passing through said lever leg end sections and through the lower end of said live lever. The upper end of this live lever 55a is pivotally connected by means of a pivot pin 56a to one end of a pull or power rod 57a operated from a lever (not shown) of the air cylinder (not shown).

For powering the lever legs 45a on the other side of the bolster 12a, there is provided an inclined dead lever 62a having its lower end extending between the offset confronting end sections 46a of said lever legs. This dead lever 62a is held in this inclined position by a pivot pin 47a passing through the corresponding lever leg end sections 46a and through the lower end of said dead lever. The upper end of the dead lever 62a is anchored to the bolster 12a by means of a link 64a consisting of a loop 70 and two shackles 71 and 72, interlinked with said loop at opposite ends thereof. The shackle 71 is pivotally connected to an anchor bracket 73 aflixed to the side of the bolster 12a, while the other shackle 72 is pivotally connected to the upper end of the dead lever 62a by means of a pivot pin 73 passing through either one of two sets of holes 75 on said shackle, according to the condition of wear of the brakes.

The dead lever 62a is operated from the live lever 55a by means of a connecting rod 60a passing through an opening 76 in the bolster 12a and having one end pivotally connected to the intermediate section of the live lever 55a by means of a pivot pin 78 passing through one of two sets of holes 80 in said connecting rod and having the other end pivotally connected to the intermediate section of the dead lever 62a by means of a pivot pin 81 passing through one of two sets of holes 82. The two sets of holes 80 and 82 at opposite ends of the connecting rod 60a, permit adjustments in the effective length of the connecting rod 60a to compensate for wear in the brake mechanisms.

The two lever legs 45a of each toggle-joint are maintained at an angle of less than 180 along their outer sides opposite the sides facing the bolster 12a. In order to prevent the two lever legs 45a in each toggle-joint from snapping out of this angular relationship during braking action, or the brake shoes 32a from withdrawing too far away from the corresponding brake discs 33 during brake releasing action, the olfset end section 46a of each lever leg 45a has a stop flange 85 (FIGS. -13) integral therewith and projecting towards the other offset end section 46a of the associated lever leg 45a. The two stop flanges 85 on associated lever legs 45a are arranged to flank the lower end of the live lever 55a in the case of one pair of associated lever legs 45:: and to flank the lower end of the dead lever 62a in the case of the other pair of associated lever legs 45a. The end sections 86 of the stop flanges 85 are curved inwardly, so that the ends 87 of these flanges serve as limiting stops adapted to be engaged by the corresponding edges of the live lever 55a and the dead lever 62a, as each of these levers reaches either of two predetermined angular positions in relation to the associated lever legs 45a. The inside limiting flanges (FIG. 8) nearest the bolster 12a are effective to prevent the brake head lever legs 45a in each toggle-joint from straightening out into exact longitudinal alignment during braking action to maintain an outside angle of less than between these lever legs during braking action, while the other outside flanges are idle. When the brakes are released, spring means (not shown) are provided in connection with the pull rod 57a to return the brake head levers 25a into idle positions, but the extent to which these brake head levers are withdrawn under spring action into brake released positions is limited by the outside limiting flanges 85 furthest from the bolster 12a, as shown in FIG. 8. The use of these outside limiting flanges 85 for determining the released positions of the brake head levers 25a is not as important as the use of these flanges for limiting the angular relationship of the two brake head levers in each toggle-joint during braking action, but it is desirable to have both set flanges, if nothing more, than to make the brake levers 25a interchangeable in each car truck.

In the operation of the brake mechanisms from the brake released positions shown in FIGS. 6-12 to braking position, the pull rod 57a is pulled to the left (FIGS. 6 and 8) and this causes the live lever 55a to swing counterclockwise about the axis of its pivot pin 47a at the lower end of said live lever. This moves the connecting rod 60a to the left, and causes the dead lever 62a to swing counterclockwise about the axis of its pivot pin 47a at the lower end of said dead lever, until the link 64a tightens up, whereupon the dead lever starts swinging clockwise about the axis of the pivot pin 74 at the upper end of said dead lever. This causes the pivot pin 47a at the lower end of the dead lever 62a to move towards the left and this causes the lever legs 45a carrying said pivot pin to straighten out short of exact longitudinal alignment. This action causes the two brake head levers 25a associated with the dead lever 62a to move angularly about the axes of the pivot pins 21 into braking positions in relation to the corresponding brake disc 33.

With the brake head levers 25a associated with the dead lever 62a immobilized into braking positions, thereby causing the connecting lever 60a to be immobilized against longitudinal movements, further movement of the pull rod 57a towards the left, causes the live lever 55a to swing counterclockwise about the axis of the pivot pin 78, and this causes the pivot pin 45a at the lower end of the live lever 55a to move towards the right. This causes the lever legs 45a carrying the pivot pin 47a at the lower end of the live lever 55a to straighten out short of exact longitudinal alignment. This action causes the two brake head levers 25a associated with the live lever 55a to move angularly about the axes of their pivot pins 21 into braking position in relation to the corresponding brake discs 33.

The braking action described in connection with the construction of FIGS. 6-12 is described as taking place in sequential steps. Actually, the movements described may take place substantially simultaneously or in sequences different from that described, but in any case, the brake head levers 250: all reach the same position, and any one brake head lever reaching immobilized braking position before the others, acts as an anchor member by which the other brake head levers are moved into their respective braking positions.

The inside limiting flanges 85 are located so that they do not interfere with the movements of the brake head levers 25a into full braking positions, but prevent the two lever legs 45a in each toggle-joint from reaching a dead center position in which the two legs are in exact longitudinal alignment by preventing the live lever 55a and the 7 dead lever 62a from reaching a corresponding angular relationship to the lever legs 45a associated therewith.

While the invention has been described with particular reference to specific embodiments, it is to be understood that it is not to be limited thereto but is to be construed broadly and restricted solely by the scope of the appended claims.

What is claimed is:

1. In a railway car truck, the combination comprising a pair of coaxial car wheels, a pair of brake discs rigid with said wheels for rotation therewith, a toggle-joint mechanism extending between said wheels and comprising two brake head levers, means supporting said brake head levers for pivotal movements int-o and out of braking relationship with respect to said brake discs, said brake head levers having rigid therewith respective legs articulated at one end, end to end out of longitudinal alignment to form an elbow joint therebetween, said brake head levers being supported for movements into braking positions in relation to said brake discs as said elbow joint is straightened out and means for applying pressure to said elbow joint in a direction tending to straighten out said elbow joint to move said brake head levers into braking positions.

2. The combination in a railway car truck as described in claim 1, comprising side frames for said truck from which said car wheels are supported, said lever supporting means being operable to support said brake head levers at substantially fixed axis points with respect to said side frames respectively.

3. The combination in a railway car truck as described in claim 1, the means for applying pressure to said elbow joint comprising an operating lever having a section pivotally secured to the articulated ends of said legs.

4. The combination in a railway car truck as described in claim 1, said brake head lever being supported for pivotal movements substantially horizontally about substantially vertical axes respectively, said lever legs at their articulated ends having substantially parallel confronting end sections respectively olfset upwardly and downwardly respectively, the means for applying pressure to said elbow joint comprising an operating lever inclined with respect to the horizontal and having a section between the offset end sections of said lever legs, and a pivot pin extending through said offset end sections of the lever legs and said section of the operating lever.

5. In a railway car truck, the combination comprising a pair of side frames, a pair of coaxial car wheels supported on said side frames, a pair of brake discs rigid with said Wheels respectively on the inboard sides thereof for rotation therewith, a toggle-joint mechanism extending between said wheels and comprising two brake head levers, means supporting said brake head levers for pivotal movements into and out of braking relationship with respect to said brake discs, each of said brake head levers having an L-shaped section comprising a first leg extending between the side frames and a second leg extending along the side frames on the inboard side of the corresponding brake disc, said lever supporting means supporting each brake head lever at the outer end of its first leg for movement about an axis fixed with respect to the corresponding side frame, to cause the second leg to move towards the corresponding brake disc into braking position or away from the latter brake disc, each of said brake head levers having rigid therewith a third leg extending from the second leg between the side frames, said third legs being articulated at one end, end to end out of longitudinal alignment to form an elbow joint therebetween, and means for applying pressure to said elbow joint in a direction tending to straighten out said elbow joint to move said brake head levers into braking positions.

6. The combination in a railway car as described in claim 5, the means for applying pressure to said elbow joint comprising an operating lever having a section pivotally joined to the articulated ends of said third lever legs 8 by means of a pivot pin passing through said operating lever section and said articulated ends of said third legs.

7. The combination in a railway car truck as described in claim 5, said lever supporting means supporting said brake head levers for angular movement substantially horizontally, said third legs at their articulated ends having respective confronting end sections offset slantingly upwardly and downwardly respectively from the main bodies of said third legs in opposite directions, so that said offset end sections are substantially parallel, said means for applying pressure to said elbow joint comprising an operating lever having a first section between said offset end leg sections and slanting in the direction of said offset end leg sections, means for pivotally supporting a second section of said operating lever, and means for applying power to a third section of said operating lever to cause said first section of the operating lever and said articulated ends of said third lever legs to move in unison about an axis through said second section of the operating lever in a direction to straighten out said elbow joint and thereby to move said brake head levers angularly into braking positions.

8. In a railway car truck, the combination of a pair of opposed side frames extending along the longitudinal direction of the truck, four wheels supported on said side frames with two wheels on each side of the truck and with each wheel on one side coaxial with a corresponding wheel on the opposite side, the axes of said wheels extending parallel between said side frames and transverse to said longitudinal direction, a truck bolster extending between said side frames for support from said side frames and located between the two pairs of coaxial wheels, brake discs rigid with said wheels respectively for rotation therewith, two toggle-joint mechanisms extending between said side frames on opposite sides of said bolster, each of said toggle-joint mechanisms comprising two brake head levers, and means supporting said brake head levers for pivotal movements into and out of braking relationship with respect to corresponding coaxial brake discs respectively, said brake head levers having rigid therewith respective legs articulated at one end, end to end out of longitudinal alignment to form an elbow joint therebetween, said brake head levers being supported for movements into braking positions in relation to said brake discs as said elbow joint is straightened out, and means for applying pressures to said elbow joints in opposite directions tending to straighten out said elbow joints.

9. The combination in a railway car truck as described in claim 8, said pressure applying means comprising a live lever having a first section pivotally joined to the elbow joint of one of the toggle-joint mechanisms, a dead lever having a first section pivotally joined to the elbow joint of the other toggle-joint mechanism, a connecting rod pivotally connected at one end to a second section of said live lever and pivotally connected at the other end to a second section of said dead lever, means for applying braking power to a third section of said live lever, and means for anchoring a third section of said dead lever against movement during the braking operation.

10. The combination in a railway car truck as described in claim 9, the first sections of said live lever and said dead lever being located intermediate the ends of said live lever and said dead lever, the second sections of said live lever and said dead lever being located at one end of said live lever and said dead lever, and the third sections of said live lever and said dead lever being located at the other ends of said live lever and said dead lever.

11. The combination in a railway car truck as described in claim 9, the first sections of said live lever and said dead lever being located at one end of said live and dead levers, the second sections of said live lever and said dead lever being located intermdiate the ends of said live and dead levers, and the third sections of said live lever and said dead lever being located at the other ends of said live and dead levers.

12. In a railway car truck, the combination of a pan of opposed side frames extending along the longitudinal direction of the truck, four wheels supported on said side frames with two wheels on each side of the truck and with each wheel on one side coaxial with a corresponding wheel on the opposite side, the axes of said wheels extending parallel between said side frames and transverse to said longitudinal direction, a truck bolster extending between said side frames and located between the two pairs of coaxial wheels, brake discs on the inboard sides of said wheels respectively rigid with said wheels respectively for rotation therewith, two toggle-joint mechanisms extending between said side frames on opposite sides of said bolster, each of said toggle-joint mechanisms comprising two brake head levers, means supporting said brake head levers for pivotal movements about respective substantially vertical axes, into and out of braking relationship with respect to said brake discs, each of said brake head levers having an L-shaped section comprising a first leg extending between the side frames and a second leg extending along the side frames on the inboard side of the corresponding brake disc, said lever supporting means supporting each brake head lever at the outer end of its first leg for movement about a substantially vertical axis fixed with respect to the corresponding side frame, to cause the second leg to move towards the corresponding brake disc into braking position or away from the latter brake disc, each of said brake head levers having rigid therewith a third leg extending from the second leg between the side frames, the third legs in each toggle-joint mechanism being articulated at one end, end to end out of longitudinal alignment to form an elbow joint there between, and means for applying pressure substantially simultaneously to said elbow joints in opposite directions tending to straighten out said elbow joints to move said brake head levers into braking positions.

13. In a railway car, the combination comprising a pair of coaxial car wheels, a toggle-joint mechanism extending between said wheels and comprising two legs articulated at one end, end to end out of alignment to form an elbow joint therebetween, means for confining the movements of the other ends of said legs in directions to bring said legs towards and away from alignment, means for applying braking pressure to said elbow joint in a direction tending to straighten out said elbow joint and thereby to bring said legs towards alignment, comprising a lever pivoted to the articulated ends of said legs, means responsive to the aligning action of said legs for braking said wheels, and stop means limiting the relative angular movements of said legs to positions short of exact longitudinal alignment, independently of the resistance offered by said braking means, said stop means comprising a stop projection on one of said legs located in position to engage said lever in limiting relative angular positions of said legs short of exact longitudinal alignment and thereby to prevent said legs from moving beyond the latter positions in their braking movements.

14. In a railway car truck, the combination comprising a pair of coaxial car wheels, a toggle-joint mechanism extending between said wheels and comprising two legs articulated at one end, end to end out of alignment to form an elbow joint therebetween, said legs at their articulated ends having overlapping end sections, means for confining the movements of the other ends of said legs in directions to bring said legs towards and away from alignment, means for applying braking pressure to said elbow joint in a direction tending to straighten out said elbow joint and thereby to bring said legs towards alignment, comprising a lever between said overlapping end sections and a pivot pin passing through said overlapping end sections and said lever to articulate the ends of said legs and at the same time to pivotally connect said lever to said elbow joint, means responsive to the aligning action of said legs for braking said Wheels, and stop means limiting the relative angular movements of said legs to positions short of exact longitudinal alignment, independently of the resistance offered by said braking means, said stop means comprising a stop flange on one of said leg sections rigid therewith and projecting towards the other leg section, said stop flange being located in position to engage said lever in limiting relative angular positions of said legs short of exact longitudinal alignment and thereby to prevent said legs from moving beyond the latter positions in their braking movements.

15'. The combination in a railway car truck as described in claim 14, the other end leg section also having a stop flange rigid therewith and projecting towards the other leg section, said stop flanges being located in positions to flank the lever at the articulated ends of the legs to limit the relative movements of said legs away from straightening action.

References Cited UNITED STATES PATENTS 340,580 4/1886 Huber 188-59 2,498,625 2/1950 Tack l88-59 2,975,869 3/1961 Busch 188-59 DUANE A. REGER, Primary Examiner. 

1. IN A RAILWAY CAR TRUCK, THE COMBINATION COMPRISING A PAIR OF COAXIAL CAR WHEELS, A PAIR OF BRAKE DISCS RIGID WITH SAID WHEELS FOR ROTATION THEREWITH, A TOGGLE-JOINT MECHANISM EXTENDING BETWEEN SAID WHEELS AND COMPRISING TWO BRAKE HEAD LEVERS, MEANS SUPPORTING SAID BRAKE HEAD LEVERS FOR PIVOTAL MOVEMENTS INTO AND OUT OF BRAKING RELATIONSHIP WITH RESPECT TO SAID BRAKE DISCS, SAID BRAKE HEAD LEVERS HAVING RIGID THEREWITH RESPECTIVE LEGS ARTICULATE AT ONE END, END TO END OUT OF LONGITUDINAL ALIGNMENT TO FORM AN ELBOW JOINT THEREBETWEEN, SAID BRAKE HEAD LEVERS BEING SUPPORTED FOR MOVEMENTS INTO BRAKING POSITIONS IN RELATION TO SAID BRAKE DISCS AS SAID ELBOW JOINT IS STRAIGHTENED OUT, AND MEANS FOR APPLYING PRESSURE TO SAID ELBOW JOINT IN A DIRECTION TENDING TO STRAIGHTEN OUT SAID ELBOW JOINT TO MOVE SAID BRAKE HEAD LEVERS INTO BRAKING POSITIONS. 